Его называют инспектором.

Because его is the form meaning him, while он means he.

The verb называть takes a direct object:

• называть кого? — to call whom?

So in Его называют инспектором, его is the person being called something.

A useful note: for masculine animate words, the accusative often looks like the genitive, so его serves as both of him and him depending on the sentence.

After verbs like называть (to call), Russian often puts the second noun—the label, role, or description—in the instrumental case.

So the pattern is:

• называть кого кем?
  to call someone something

That is why you get:

• его — the person being called something
• инспектором — what he is being called

This same pattern appears in many similar sentences:

• Его считают гением. — They consider him a genius.
• Её сделали директором. — They made her director.

Называют is the 3rd person plural present tense form of называть.

So literally it is they call.

But Russian very often uses 3rd person plural with no subject to mean something like:

• people call
• they call
• one calls

So the sentence does not necessarily mean a specific group of people. It can simply mean that this is what people generally call him.

Russian often leaves out the subject when it is vague or unimportant.

In English, we may say:

• They say...
• They call him...
• People think...

Russian does the same thing very naturally:

• Его называют инспектором.

Here, they does not point to specific people unless the context makes that clear. It often just means people in general.

Usually it means a general or habitual fact:

• People call him an inspector
• He is referred to as an inspector

Because называть is imperfective, the present tense often describes something regular, repeated, or generally true.

If you wanted a single completed past event, Russian would more likely use a perfective form, for example:

• Его назвали инспектором. — They called him an inspector / They named him inspector.

So называют usually sounds more ongoing or general than назвали.

This is a very common question.

Зовут is most often used for a person’s name:

• Его зовут Иван. — His name is Ivan.
• Как вас зовут? — What is your name?

Называют is used when people call someone something, often as a title, description, nickname, or label:

• Его называют инспектором. — They call him an inspector.
• Её называют гением. — They call her a genius.

So:

• зовут = what someone’s name is
• называют = what people refer to someone as

By itself, it most directly means that people call him an inspector.

Whether he really is one depends on the context.

Russian называть can be used for:

• a real title or role
• a nickname
• a description people use
• even a label someone may disagree with

So the sentence itself focuses on the name/label used, not necessarily on whether the label is objectively true.

Yes. Russian word order is flexible, and changing it usually changes emphasis, not the basic meaning.

The version you gave:

• Его называют инспектором.

is a natural, neutral way to say it.

Other orders are possible, for example:

• Инспектором его называют. — puts more emphasis on inspector
• Его инспектором называют. — can also work, with a slightly different focus

So the core grammar stays the same, but the information structure shifts.

Because Russian has no articles like a, an, or the.

So инспектором could correspond to:

• an inspector
• the inspector
• sometimes just inspector

The exact choice in English depends on context.

This is normal in Russian: article meaning is usually understood from the situation rather than from a separate word.

The dictionary form is инспектор.

Инспектором is the instrumental singular form.

So the pattern is:

• nominative: инспектор
• instrumental: инспектором

For many masculine nouns, the instrumental singular ending is -ом or -ем. Here it is -ом, giving инспектором.